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Hi everyone,

Im hoping someone can help with this problem ive been having. I have a Heat pump system with 3 zones being controlled by a Honeywell HZ322 board. This problem has been going on for over a year now. Heres what happens: The AC will work completely fine for weeks/months (all zones on schedule turning on and off no issue). Then all of a sudden, a zone wont kick on when the Thermostat calls for AC (If all other zones are off in the house i can hear the AC unit kick on when the Thermostat calls and it will run continuously, but no air comes out of the registers). This will happen for a few minutes/hour/day and then work fine again until a week or two later when it happens again and then it gets progressively worse until its happening every day. Sometimes its the same zone malfunctioning, other times its all of them, and sometimes its a mix (completely random which zones work/dont and when). Last night for example the AC on zone 1 worked fine all day and all night, zone 2 was sometimes working/sometimes not and the 3rd zone just refused to work. I wake up this morning and the 3rd zone (our sleeping area) didnt work all night. i turn the thermostat off and then back on and it started working and is running fine right now lol.

Ive had HVAC guys out several times. The first time they replaced a damper and said the motor went bad (the problem resolved itself for a while then started up again). The next time they were here for hours troubleshooting and had to call in a supervisor for another opinion. They ended up replacing the control board (i think they couldnt figure it out so just thought it must be that). Each time the problem resolves itself for days/weeks/months then returns.

Things ive tried when its acting up: Ive tried shutting off all zones for several hours, ive tried turning the power off at the breaker for 20-30minutes, ive tried having the thermostat fan settings to always on.

Does anyone have any idea what could be happening here?

Thanks in advance for the help, this has been super frustrating and im really hoping i can avoid another call to the HVAC guys (or at least have a better idea of whats going on so i can point them in the right direction

Thanks - Tim
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